Robot cleaners are apparatuses that suction foreign substances such as dust from a floor surface while traveling in an area to be cleaned without user's manipulation so as to perform a cleaning operation. Robot cleaners determine a distance to obstacles such as furniture, office supplies, walls installed in the area to be cleaned using a distance sensor and drive a left-wheel motor and a right-wheel motor of a robot cleaner selectively to clean the area to be cleaned while changing a direction.
A suction unit is disposed on a bottom surface of the robot cleaner, and dust on the floor surface is suctioned by the suction unit. A suction motor is provided in the robot cleaner and supplies a suction force so that dust on the floor surface can be suctioned by the suction unit. A main brush is rotatably provided at the suction unit to pick up dust on the floor surface.
Dust suctioned by the suction unit can be accommodated in a dust collector. A filter is provided at one side of the dust collector. The filter filters air suctioned into a suction motor side and discharges the air. When cleaning of the floor surface is performed by the robot cleaner for a long time, the foreign substances are filtered by the filter such that the filter may be clogged. When the filter is clogged, the suctioned air does not easily pass through the filter so that the suction force generated by the suction motor may be reduced and cleaning efficiency may be degraded.
In order to solve the problem of a lowered suction force, applying a cyclone dust collector to the robot cleaner may be considered. The cyclone dust collector is required to be manufactured in an appropriate ratio and an appropriate size so as to have a small pressure loss and high dust-collecting efficiency.